The was an amphibious

medium tank A medium tank is a classification of tanks, particularly prevalent during World War II, which represented a compromise between the mobility oriented light tanks and the armour and armament oriented heavy tanks. A medium tank's classification ...

developed by the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, Potsdam Declaration, when it was dissolved followin ...

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. The Type 3 Ka-Chi was based on an extensively modified

Imperial Japanese Army The Imperial Japanese Army (IJA; , ''Dai-Nippon Teikoku Rikugun'', "Army of the Greater Japanese Empire") was the principal ground force of the Empire of Japan from 1871 to 1945. It played a central role in Japan’s rapid modernization during th ...

Type 1 Chi-He medium tank (it had 2 more road-wheels and two more return rollers on each side) and was a larger and more capable version of the earlier Type 2 Ka-Mi amphibious tank.

History and development

The success of the Type 2 Ka-Mi design pleased the planners in the

Imperial Japanese Navy General Staff The was the highest organ within the Imperial Japanese Navy (IJN). In charge of planning and operations, it was headed by an Admiral headquartered in Tokyo. History Created in 1893, the Navy General Staff took over operational (as opposed to a ...

, and it was determined that a larger version with stronger armor and armament would be useful in future

amphibious warfare Amphibious warfare is a type of offensive military operation that today uses naval ships to project ground and air power onto a hostile or potentially hostile shore at a designated landing beach. Through history the operations were conduc ...

operations. The Type 3 Ka-Chi prototype was completed in late 1943 and the first units entered service that same year. Only 12 to 19 Type 3 Ka-Chi's were built from 1943 to 1945.Taki's Imperial Japanese Army: Type 3 Amphibious Tank "Ka-Chi"
/ref> This was due to the fact that the main priorities of the Japanese Navy were in warship and aircraft production, and lacking in any definite plans for additional amphibious operations, production of the Type 3 Ka-Chi remained a very low priority.

Design

The Type 3 Ka-Chi was based on a heavily modified version of the chassis of the army's Type 1 Chi-He medium tank, and thus featured considerably better armored protection and firepower than the earlier Type 2 Ka-Mi. It had smooth sides that faired into front and rear flotation pontoons made of sheet-metal. The front pontoon had a curved ' bow' shape and both pontoons could be jettisoned from inside the tank once the tank had landed. However, in practice, the pontoons were usually retained, as they provided some marginal additional protection against enemy fire. The undercarriage used the Hara system, with the addition of 2 more road-wheels and two more return rollers on each side than the Type 1 Chi-He. The hull was welded and water-proofed "with rubber seals and gaskets". The water propulsion was provided by twin-screws and it had two steering screws. The Type 3 Ka-Chi had a distinctive large snorkel behind the turret for aerating the

diesel engine The diesel engine, named after the German engineer Rudolf Diesel, is an internal combustion engine in which Combustion, ignition of diesel fuel is caused by the elevated temperature of the air in the cylinder due to Mechanics, mechanical Compr ...

more efficiently and keeping the exhaust free of water. The main gun of Type 3 Ka-Chi was the

Type 1 47 mm tank gun The was an anti-tank gun developed by the Imperial Japanese Army, and used in combat during World War II. The Type 1 47mm anti-tank gun was optimized for truck drawn operation. The Type 1 number was designated for the year the gun was accepted, 2 ...

with a barrel length of 2.250 meters (L/48), EL angle of fire by −15 to +20 degrees, AZ angle of fire of 20 degrees,

muzzle velocity Muzzle velocity is the speed of a projectile (bullet, pellet, slug, ball/ shots or shell) with respect to the muzzle at the moment it leaves the end of a gun's barrel (i.e. the muzzle). Firearm muzzle velocities range from approximately t ...

by 810 m/s and penetration of 55 mm/100 m, 40 mm/500 m, and 30 mm/1,000 m.Taki's Imperial Japanese Army: "Tank Guns"
/ref> This was the same 47 mm gun used on the army's

Type 97 Shinhoto Chi-Ha Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

. Secondary armament was a coaxial Type 97 heavy tank machine gun and a hull mounted weapon of the same type. The

gun turret A gun turret (or simply turret) is a mounting platform from which weapons can be fired that affords protection, visibility and ability to turn and aim. A modern gun turret is generally a rotatable weapon mount that houses the crew or mechanis ...

was designed with an extended circular

cupola In architecture, a cupola () is a relatively small, usually dome-like structure on top of a building often crowning a larger roof or dome. Cupolas often serve as a roof lantern to admit light and air or as a lookout. The word derives, via Ital ...

to keep the hatch above water. The vehicle required a crew of seven, one of whom (as with the Type 2 Ka-Mi) served as an on-board mechanic.

Service record

The Type 3 Ka-Chi was produced in very limited numbers, but proved useful due to its capability to be launched from a

submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...

, which enabled it to accommodate the increasingly difficult task of daytime reinforcement for isolated island garrisons located in the

South Pacific The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

and in

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

. The Type 3 Ka-Chi was deployed only in the Japan homeland and did not see combat.

Notes

References

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External links